package de.lmu.mvs.lerngruppenfinder;

import java.io.IOException;

import com.eclipsesource.json.JsonArray;
import com.eclipsesource.json.JsonObject;
import com.eclipsesource.json.JsonValue;

import de.lmu.mvs.lerngruppenfinder.utils.BaseActivity;
import de.lmu.mvs.lerngruppenfinder.utils.Constants;
import de.lmu.mvs.lerngruppenfinder.utils.FileApi;
import de.lmu.mvs.lerngruppenfinder.utils.ServerConnector;
import de.lmu.mvs.lerngruppenfinder.utils.FileApi.UserCredentials;
import de.lmu.mvs.lerngruppenfinder.utils.ServerConnector.ServerConnectorListener;
import de.lmu.mvs.lerngruppenfinder.utils.ServerConnector.ServerError;
import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

/**
 * Activity which displays a login screen to the user
 */
public class LoginActivity extends BaseActivity {


	/**
	 * Keep track of the login task to ensure we can cancel it if requested.
	 */
	private UserLoginTask mAuthTask = null;

	// Values for email and password at the time of the login attempt.
	private String mEmail;
	private String mPassword;

	// UI references.
	private EditText mEmailView;
	private EditText mPasswordView;
	private View mLoginFormView;
	private View mLoginStatusView;
	private TextView mLoginStatusMessageView;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		//		overridePendingTransition(R.anim.anim_slide_in, R.anim.anim_slide_out);
		setContentView(R.layout.activity_login);
		

		// Set up the login form.
		mEmailView = (EditText) findViewById(R.id.email);
		mEmailView.setText(mEmail);

		mPasswordView = (EditText) findViewById(R.id.password);
		mPasswordView
		.setOnEditorActionListener(new TextView.OnEditorActionListener() {
			@Override
			public boolean onEditorAction(TextView textView, int id,
					KeyEvent keyEvent) {
				if (id == R.id.login || id == EditorInfo.IME_NULL) {
					attemptLogin();
					return true;
				}
				return false;
			}
		});

		mLoginFormView = findViewById(R.id.login_form);
		mLoginStatusView = findViewById(R.id.login_status);
		mLoginStatusMessageView = (TextView) findViewById(R.id.login_status_message);

		findViewById(R.id.sign_in_button).setOnClickListener(
				new View.OnClickListener() {
					@Override
					public void onClick(View view) {
						attemptLogin();
					}
				});
		
		
		checkStoredCredentials();
	}


	/**
	 * Attempts to sign in the account specified by the login form.
	 * If there are form errors (invalid email, missing fields, etc.), the
	 * errors are presented and no actual login attempt is made.
	 */
	public void attemptLogin() {
		if (mAuthTask != null) {
			return;
		}

		// Reset errors.
		mEmailView.setError(null);
		mPasswordView.setError(null);

		// Store values at the time of the login attempt.
		mEmail = mEmailView.getText().toString();
		mPassword = mPasswordView.getText().toString();

		boolean cancel = false;
		View focusView = null;

		// Check for a valid password.
		if (TextUtils.isEmpty(mPassword)) {
			mPasswordView.setError(getString(R.string.error_field_required));
			focusView = mPasswordView;
			cancel = true;
		} else if (mPassword.length() < 4) {
			mPasswordView.setError(getString(R.string.error_invalid_password));
			focusView = mPasswordView;
			cancel = true;
		}

		// Check for a valid email address.
		if (TextUtils.isEmpty(mEmail)) {
			mEmailView.setError(getString(R.string.error_field_required));
			focusView = mEmailView;
			cancel = true;
		} else if (!mEmail.contains("@")) {
			mEmailView.setError(getString(R.string.error_invalid_email));
			focusView = mEmailView;
			cancel = true;
		}

		if (cancel) {
			// There was an error; don't attempt login and focus the first
			// form field with an error.
			focusView.requestFocus();
		} else {
			// Show a progress spinner, and kick off a background task to
			// perform the user login attempt.
			mLoginStatusMessageView.setText(R.string.login_progress_signing_in);
			showProgress(true);
			mAuthTask = new UserLoginTask();
			mAuthTask.execute((Void) null);
		}
	}

	/**
	 * Shows the progress UI and hides the login form.
	 */
	@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
	private void showProgress(final boolean show) {
		// On Honeycomb MR2 we have the ViewPropertyAnimator APIs, which allow
		// for very easy animations. If available, use these APIs to fade-in
		// the progress spinner.
		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) {
			int shortAnimTime = getResources().getInteger(
					android.R.integer.config_shortAnimTime);

			mLoginStatusView.setVisibility(View.VISIBLE);
			mLoginStatusView.animate().setDuration(shortAnimTime)
			.alpha(show ? 1 : 0)
			.setListener(new AnimatorListenerAdapter() {
				@Override
				public void onAnimationEnd(Animator animation) {
					mLoginStatusView.setVisibility(show ? View.VISIBLE
							: View.GONE);
				}
			});

			mLoginFormView.setVisibility(View.VISIBLE);
			mLoginFormView.animate().setDuration(shortAnimTime)
			.alpha(show ? 0 : 1)
			.setListener(new AnimatorListenerAdapter() {
				@Override
				public void onAnimationEnd(Animator animation) {
					mLoginFormView.setVisibility(show ? View.GONE
							: View.VISIBLE);
				}
			});
		} else {
			// The ViewPropertyAnimator APIs are not available, so simply show
			// and hide the relevant UI components.
			mLoginStatusView.setVisibility(show ? View.VISIBLE : View.GONE);
			mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
		}
	}

	/**
	 * Represents an asynchronous login task used to authenticate
	 * the user.
	 */
	public class UserLoginTask extends AsyncTask<Void, Void, Boolean> {

		protected Boolean success = false;
		protected Boolean loginRunning = true;
		protected Boolean interestSaving = true;

		@Override
		protected Boolean doInBackground(Void... params) {

			ServerConnector.login(new ServerConnectorListener<JsonObject>() {

				@Override
				public void requestFinished(JsonObject json) {
					success = true;
					loginRunning = false;
					try {
						storeUserCredentials(json, mPassword);
						
						FileApi.writeJsonToStorage(json, "UserCredentials", LoginActivity.this);
					} catch (IOException e) {
						Log.e(STORAGE_SERVICE, e.toString());
					}
				}

				@Override
				public void requestError(ServerError error) {
					Log.e("login", error.getErrorMessage());
					loginRunning = false;
				}
			}, mEmail, mPassword);

			while(loginRunning && interestSaving){
				try {
					Thread.sleep(100);
				} catch (InterruptedException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			return success;
		}

		@Override
		protected void onPostExecute(final Boolean success) {
			mAuthTask = null;
			showProgress(false);

			if (success) {
				loadUserData();
			} else {
				mPasswordView
				.setError(getString(R.string.error_incorrect_password));
				mPasswordView.requestFocus();
			}
		}

		@Override
		protected void onCancelled() {
			mAuthTask = null;
			showProgress(false);
		}
	}

	private void loadUserData(){
		JsonValue json = FileApi.readJsonFromStorage(Constants.USER_CREDENTIALS, this);

		if(json != null){
			int id = Integer.parseInt(json.asObject().get("id").asString());
			ServerConnector.getUserInterests(new ServerConnectorListener<JsonArray>() {

				@Override
				public void requestFinished(JsonArray json) {
					try {
						FileApi.writeJsonToStorage(json, Constants.USER_INTERESTS, LoginActivity.this);
						startDashboard();
						finish();
					} catch (IOException e) {
						e.printStackTrace();
					}
				}

				@Override
				public void requestError(ServerError error) {
					Log.e("Login", error.getErrorMessage());
					startDashboard();
					finish();
				}
			}, id);
		}
	}
	
	private boolean checkStoredCredentials(){
		UserCredentials userCredentials = FileApi.readLoginCredentials();
		if(userCredentials != null){
			// is logged in
			mEmail = userCredentials.mail;
			mPassword = userCredentials.password;
			
			mLoginStatusMessageView.setText(R.string.login_progress_signing_in);
			showProgress(true);
			mAuthTask = new UserLoginTask();
			mAuthTask.execute((Void) null);
			return true;
		} else {
			return false;
		}
	}
	
	/**
	 * Store user credentials in shared prefs
	 * @param json
	 */
	private void storeUserCredentials(JsonObject json, String password){
		try {
			int id = Integer.parseInt(json.get("id").asString());
			String mail = json.get("mail").asString();
			
			FileApi.storeLoginCredentials("", mail, password, id);
		} catch(NumberFormatException e){
			// FIXME return to usual login
		}
	}

	protected void startDashboard() {
		startActivity(new Intent(this, DashboardActivity.class));
		finish();
	}

	public void startRegisterActivity(View view) {
		startActivity(new Intent(this, RegisterActivity.class));
	}

	public void startPasswordResetActivity(View view) {
		startActivity(new Intent(this, PasswordResetActivity.class));
	}
}

